Sensation & Perception Flashcards
What is sensation?
The detection of physical energy by sense organs, which then send information to the brain
What is perception?
The brain’s interpretation of raw sensory inputs
What is transduction?
The process of converting an external energy to substance into neural energy
What is a sense receptor?
A specialised cell responsible for converting external stimuli into neural activity for a specific sensory system
What is absolute threshold?
The lowest level of a stimulus needed for the nervous system to detect a change 50% of the time
What is just noticeable difference (JND)?
The smallest change in the intensity of a stimulus that we can detect
What is the signal detection theory?
The psychophysical theory which describe the detection of stimuli under conditions of uncertainty
What is cross-modal processing?
The mixing of senses across brain areas
What are some examples of cross-modal processing?
McGurk effect
Rubber hand illusion
Synaesthesia
What is selective attention?
The process of selecting one sensory channel and ignoring or minimising the others
True or False: perception is an exact translation of our sensory experiences into neural activity
False
True or False: in signal detection theory, false alarms and misses help us to measure hoe much someone is paying attention
False
True or False: cross-modal activation often helps us to process information more accurately
True
True or False: selective attention may blind us to what is happening right in front of our noses
True
True or False: synchronised alpha oscillations (8-12Hz) in different regions of the cortex are used by the brain to coordinate separate processing activities (the binding problem)
False
What is brightness?
The intensity of the reflected light that reaches our eyes
What is hue?
The colour of light lenses
What is accommodation (perception)?
Changing the shape of the lens to focus on objects near or far
What is the fovea?
The part of the retina where light rays are most sharply focused. Only contains cones
What is acuity?
The sharpness of vision
What is the photopigment in rods?
Rhodopsin
What are ganglion cells?
Nerve cells that transmit visual information from the eye to the brain
What is the trichromatic theory?
The idea that colour vision is based on our sensitivity to three different colours (blue, green and red)
How many different types of cones are there?
Three
What is the opponent process theory?
The idea that we perceive colour as either red or green, or as either blue or yellow
What is blindsight?
The remarkable phenomenon in which people with cortical blindness can make correct guesses about things in their environment, even though they cannot see them
What is visual agnosia?
A deficit in perceiving objects; they can see the object but are unable to identify it correctly
True or False: the visible spectrum of light differs across species and can differ across individuals
True
True or False: the lens of the eye changes shape depending on whether lighting conditions are bright or dim
False
True or False: although we perceive objects as unified wholes, different parts of our brain process different kinds of visual information, such as shape, colour and motion
True
True or False: red-green colour blindness results when rods are missing but cones are intact
False
True or False: people with visual agnosia have difficulty naming objects
True
What causes colour blindness?
The absence or reduced number of one or more types of cones
What is timbre?
The complexity or quality of sound that makes musical instruments, human voices or other sources sound unique
What is a cochlea?
A bony, spiral-shaped sense organ used for hearing. Vibrations from sound waves disturb the fluid in the cochlea and travel to the base, where pressure is released and transduction occurs
What is the organ of Corti?
Tissue containing the hair cells necessary for hearing
What is the basilar membrane?
The membrane supporting the organ of Corti and hair cells in the cochlea
What are the different parts of the ear?
Outer
Middle
Inner
What does the outer ear consist of?
Pinna
Ear canal
Tympanic membrane
What is the pinna?
The part of the ear we can see, namely its skin and cartilage flap
What is the tympanic membrane?
The eardrum
What does the middle ear consist of?
Ossicles
What are the ossicles?
The three tiniest bones in the body - named the hammer, anvil and stirrup - which vibrate at the frequency of the sound wave, transmitting it from the the tympanic membrane to the inner ear
What does the inner ear consist of?
Cochlea
Semicircular canal
What is the semicircular canal?
Three fluid filled structures that play a role in balance
What is the place theory?
a theory of hearing which states that our perception of sound depends on where each component frequency produces vibrations along the basilar membrane.
What is frequency theory?
A theory that states that the frequency of the auditory nerve’s impulses corresponds to the frequency of a tone, which allows us to detect its pitch.
What is the volley theory?
states that groups of neurons of the auditory system respond to a sound by firing action potentials slightly out of phase with one another so that when combined, a greater frequency of sound can be encoded and sent to the brain to be analyzed
What is conductive deafness?
Deafness due to the malfunctioning of the ear, especially a failure of the eardrum or the ossicles
What is nerve deafness?
Deafness due to damage to the auditory nerve
What is noice-induced hearing loss?
Loss of hearing due to the damage of hair cells due to exposure to loud noises
True or False: sound waves are converted to neural impulses by creating vibrations of the fluid inside the cochlea
True
True or False: we can determine the location of a sound because the pitch seems higher in the closer ear
False
True or False: place theory states that each hair cell in the inner ear has a particular pitch or frequency with which it is most responsive
True
True or False: as we age, we tend to lose hearing for low-pitched sounds more than high-pitched sounds
False
What is a perceptual set?
The relation between a stimulus and its context. Grouping things together that make sense
What are perceptual constancies?
The process by which we perceive stimuli consistently across varied conditions
What are Gestalt principles?
Rules that govern hoe we perceive objects as whiles within their overall context
What are the different Gestalt principles?
Proximity Similarity Closure Figure-ground Symmetry Good continuation
What is a bistable image?
An image we can perceive in one of two ways
What is depth perception?
Our ability to judge distance and three-dimensional relations
What are monocular depth cues?
Stimuli that enable us to judge depth using only one eye
What is a binocular depth cue?
Stimuli that enable us to judge depth using both eyes
What are some examples of monocular depth cues?
Size Texture gradient (detail) Interposition (objects in front/behind) Linear perspective Height in plane Light and shadow
What are some examples of binocular depth cues?
Binocular disparity
Binocular convergence
What is binocular disparity?
The difference between the images of each each. The more similar the image, the further the object is away
What is binocular convergence?
The extent to which our eye muscles are causing our eyes to look inwards. The more inwards our eyes, the closer the object
True or False: in top-down processing we construct a whole stimulus from its parts
False
True or False: we perceive depth only when we have two slightly different view from our eyes
False
True or False: the firing rate of even a single neuron can code the presence of a perceptual Gestalt
True
True or False: the earths atmosphere enlarges the appearance of the moon, creating the moon illusion
False
What is bottom-up processing?
Constructing a whole stimulus from its parts. For example: perceiving an object on the basis of its edges
What is top-down processing?
Perceiving a stimulus based on our expectations on what it should be
What is the binding problem?
Our brain processes different elements (shape, size, colour etc.) of an object in different areas. Any of these elements alone do not reflect the entire object but when the come together the object can be interpreted
How many rods are there per ganglion cell?
120 rods
How many cones are there per ganglion cell?
6 cones
What is the photopigment in cones?
Photopsin